IBM Support

PI92486: VSAM DYNAMIC BUFFER ADDITION (DBA) SETTING

A fix is available

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • VSAM dynamic buffer addition (DBA).
    
    In z/OS 2.2 DFSMS VSAM introduced Dynamic Buffer addition (DBA)
    capability for LSR pools. The goal was to avoid failing a
    request due to buffer shortages. The solution was to add
    buffers to LSR pool as needed. The particular scenario targeted
    was upgrade set problems, due to running out of buffers half
    way through, having updated the AIX but not the base.
    
    If DBA is active VSAM produces a new message when buffers are
    added
    
    IDA9990I VSAM DBA ADDED xxxxDATA|INDEX BUFFERS of yyyyyBYTES
    EACH TO SHRPOOL zzzBECAUSE THERE WERE INSUFFICIENT BUFFERS TO
    PROCESS THE REQUEST.
    RECOMMENDATION: FOR PERFORMANCE, REBUILD THE SHARED POOL WITH
    AN INCREASE IN SIZE.
    
    The problem with DBA is that it decides how many buffers to add
    based on the string number and will add a significant number of
    buffers. These are added permanently and not deleted.
    
    Production of this new message and the addition of buffers is
    causing concern and generating PMRs from customers. There is
    no way for the user to turn off DBA.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: Disable VSAM Dynamic Buffer Addition    *
    *                      for CICS LSRPOOLs.                      *
    ****************************************************************
    VSAM Dynamic Buffer Addition ( DBA ) causes too many buffers to
    be added for CICS LSRPOOLs. DBA is not a substitute for well
    tuned LSRPOOLs.
    

Problem conclusion

  • CICS File Control has been changed to specify DBA=NO on the
    BLDVRP macros issued to build LSRPOOLs to disable Dynamic
    Buffer Addition.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI92486

  • Reported component name

    CICS TS Z/OS V5

  • Reported component ID

    5655Y0400

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2018-01-16

  • Closed date

    2018-02-06

  • Last modified date

    2018-03-01

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    UI53678 UI53679 UI53680 UI53681

Modules/Macros

  • DFHFCL
    

Fix information

  • Fixed component name

    CICS TS Z/OS V5

  • Fixed component ID

    5655Y0400

Applicable component levels

  • R000 PSY UI53681

       UP18/02/07 P F802

  • R100 PSY UI53680

       UP18/02/07 P F802

  • R800 PSY UI53678

       UP18/02/07 P F802

  • R900 PSY UI53679

       UP18/02/08 P F802

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.1","Edition":"","Line of Business":{"code":"LOB35","label":"Mainframe SW"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.1","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
01 March 2018